\begin{table}[htbp]\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\caption{Summary statistics for restricted samples: 2002 and 2007}
\begin{tabular}{l*{4}{ccc}}
\toprule
               &\multicolumn{3}{c}{(1)}            &\multicolumn{3}{c}{(2)}            &\multicolumn{3}{c}{(3)}            &\multicolumn{3}{c}{(4)}            \\
               &\multicolumn{3}{c}{High predicted probability of work for mothers}&\multicolumn{3}{c}{Table 2 baseline}&\multicolumn{3}{c}{Positive childcare expenditures}&\multicolumn{3}{c}{Table 4 baseline}\\
               &          N&       Mean&         SD&          N&       Mean&         SD&          N&       Mean&         SD&          N&       Mean&         SD\\
\midrule
$\ln(\tilde{W}\_{m})$&        928&       2.49&       0.62&        727&       2.51&       0.62&        384&       2.56&       0.52&        322&       2.58&       0.53\\
$\ln(\tilde{W}\_{f})$&        662&       2.98&       0.60&        451&       2.96&       0.56&        247&       2.86&       0.53&        213&       2.86&       0.51\\
$\ln(\tilde{P}\_{c,i})$&       1156&       1.10&       0.32&        727&       1.10&       0.32&        423&       1.10&       0.33&        347&       1.10&       0.33\\
Child's age    &       1156&       9.60&       2.05&        727&       9.64&       2.01&        423&       8.34&       1.95&        347&       8.36&       1.95\\
Mother HS grad &       1156&       0.31&       0.46&        727&       0.29&       0.45&        422&       0.25&       0.43&        347&       0.25&       0.44\\
Mother some coll.&       1156&       0.35&       0.48&        727&       0.34&       0.47&        422&       0.37&       0.48&        347&       0.35&       0.48\\
Mother coll+   &       1156&       0.33&       0.47&        727&       0.36&       0.48&        422&       0.33&       0.47&        347&       0.35&       0.48\\
Mother's age   &       1156&      37.87&       6.36&        727&      37.92&       6.28&        423&      35.92&       6.22&        347&      36.00&       6.36\\
Father HS grad &        744&       0.40&       0.49&        491&       0.42&       0.49&        265&       0.35&       0.48&        227&       0.35&       0.48\\
Father some coll.&        744&       0.26&       0.44&        491&       0.27&       0.44&        265&       0.23&       0.42&        227&       0.22&       0.42\\
Father coll+   &        744&       0.32&       0.47&        491&       0.30&       0.46&        265&       0.34&       0.48&        227&       0.35&       0.48\\
Father's age   &        744&      40.72&       6.99&        491&      40.51&       6.86&        264&      38.71&       6.73&        227&      38.74&       6.84\\
Mother white   &       1156&       0.57&       0.50&        727&       0.59&       0.49&        421&       0.56&       0.50&        347&       0.56&       0.50\\
Num children age 0-5&       1156&       0.14&       0.37&        727&       0.13&       0.36&        423&       0.34&       0.50&        347&       0.34&       0.50\\
Num of children&       1156&       1.98&       0.70&        727&       1.97&       0.66&        423&       1.87&       0.61&        347&       1.87&       0.58\\
Year 2007      &       1156&       0.20&       0.40&        727&       0.19&       0.39&        423&       0.04&       0.20&        347&       0.05&       0.22\\
\bottomrule
\end{tabular}
\end{table}
